How Many Dicks Challenge, or HMDC for short, is an objective grading scale that determines how many dicks could figuratively theoretically fit on a person (usually a girl). There are no real rules except for what it is, that it is determined by people who know the person being graded, and that the number cannot be changed once it is assigned. The HMDC can tell how hot a person is or even how slutty they are, or nothing at all.
The current record is 44.
Some factors to consider are: available surface area (for the dicks), hotness, and annoyingness (this lowers it).

"So what do youthink about the girls in our chem class?"
"On the HMDC? Some are 15 some are more like 32."